I am new to investing in REE’s and am doing some research. Can...

I am new to investing in REE’s and am doing some research. Can you make money out of REE’s at 2.6% TREO? Mt. Weld (Lynas) has 4.4% head grade and the Mountain Pass REE mine in California has over 6% head grade. I know that some ionic clay REE mines can have very low grades but they are easier to process and they comprise of over 80% Heavy Rare Earths. The Lindian carbonatite is a hard rock deposit and I can’t find any other mine that is extracting hard rock at such low grades. I am aware of some mines reprocessing old material like monazite and old tailings such as Rainbow in South Africa, so they are not comparable. Can anyone point to a comparable REE mine operating profitably with grades as low as 2.6% in a carbonatite?